JP5773814B2 - Construction method of wall rail of overhanging PC bridge - Google Patents

Description

  The present invention relates to a method for constructing a wall rail of a prestressed concrete bridge (PC bridge) constructed by an overhanging construction method.

  Conventionally, for example, a concrete wall rail for preventing vehicle falling or the like is provided at both ends of the roadway of the bridge superstructure. As a construction method of the concrete wall rail for installing the concrete wall rail to the bridge superstructure by the overhanging construction method, the height from the ground to the overhanging slab is low, and there are no rivers or roads under the overhanging slab, Under the construction conditions where the support work can be assembled from the ground, after the main girder including the overhanging slab of the bridge superstructure is completed, the support work is assembled from the ground to the overhanging slab. A method is known in which a formwork and a reinforcing bar are assembled and concrete on a wall rail is placed.

  However, in the bridge superstructure by the overhanging construction method, the height from the ground to the overhanging slab is often high, and there are rivers and roads below the overhanging slab, and the support work can be assembled from the ground. Often not. As a construction method for concrete wall rails under such construction conditions, after the main girder including the overhanging slab of the bridge superstructure is completed, a support is attached to the overhanging slab, and the support attached to the overhanging slab is attached. A method of assembling a formwork and a reinforcing bar and placing concrete on a wall rail is known.

  In addition to the method using cast-in-place concrete as described above, the concrete wall railing method is a method of installing a precast concrete wall railing (see, for example, Patent Document 1) or a half precast wall serving as the wall railing outer surface. A method using a member (for example, see Patent Document 2) is known.

  Here, when the bridge superstructure is constructed by the overhanging construction method, it is known that the height of the upper surface of the overhanging slab changes at the construction stage. Specifically, for example, in a prestressed concrete bridge, every time the bridge superstructure is overhanged, the tip of the overhanging bridge superstructure is displaced downwards with the maximum pier position of the overhang base being the minimum, and the bridge superstructure When pre-stress in the direction of the bridge axis is introduced, the displacement is reversed in the opposite direction. Moreover, when the prestress in the bridge axis direction is introduced to the bridge superstructure by tensioning the continuous cable after completion of the overhang construction of the bridge superstructure, the span is displaced upwards at the maximum. In addition to the change in the height of the upper surface of the overhanging slab at the construction stage, long-term and temporal displacement of the concrete itself due to creep and the displacement of the concrete itself due to temperature change, etc. It is also known that the height changes.

  In the construction of the concrete wall rails to the bridge superstructure by the overhanging construction method, the height of the overhanging floor slab upper surface as described above is predicted and the placement height of the main girder and floor slab concrete is determined. In addition, it is difficult to accurately predict the height change of the upper surface of the overhanging slab, and some errors are inevitable. However, the height of the wall height column and the finish of the plane alignment are close to the line of sight of the vehicle occupant when traveling on the road, so that even a slight error can be clearly recognized. Therefore, high accuracy is required for the height of the wall rails and the finish of the planar alignment.

  In consideration of the above-mentioned change in the height of the upper surface of the overhanging slab and the accuracy required for the wall column, when the concrete wall column is installed in the bridge superstructure by the overhang construction method, the overhanging slab of the bridge superstructure is included. After all the main girders are completed and the continuous cable is tensioned to introduce prestress in the bridge axis direction to the bridge superstructure, that is, when the height change of the upper surface of the overhanging slab has decreased, the concrete covering the entire bridge It was normal to construct the wall rails together.

JP 2001-193015 A JP 2001-279852 A

  In the construction of the concrete wall rails to the bridge superstructure by the overhanging construction method, as described above, after the main girders including the overhanging slabs of the bridge superstructure have been completed, the concrete wall rails over the entire bridge are to be constructed. In order to do this, a scaffolding will be provided outside the both ends of the overhanging slab of the bridge superstructure, and in some cases, a support work will be assembled from the ground, or a work carriage will be installed separately. Therefore, the construction period takes a long time, and the construction takes a lot of labor and cost.

  For example, when constructing a concrete wall rail with cast-in-place concrete for the bridge superstructure by the overhanging construction method, it is necessary to lay support and formwork at both ends of the overhanging slab, Dangerous work is unavoidable due to work at height.

  In addition, when installing a concrete wall rail by installing a precast concrete wall rail to the bridge superstructure by the overhanging construction method, there are few adjustment margins for the installation direction, height and inclination, so the height change of the installation position If is large, it is difficult to adjust the installation position. In addition, it is necessary to work from the outside of both ends of the overhanging slab of the bridge superstructure and to pay off the work scaffolding, so it is difficult to avoid dangerous work because it is a high place work.

  In addition, when constructing a concrete wall rail using half precast, which is the outer surface of the wall rail, for the bridge superstructure by the overhang construction method, there are few adjustment margins for the direction, height and inclination of the half precast, so the concrete wall There is a risk that the finish accuracy of the handrail will be lowered. In addition, it is necessary to work from the outside of both ends of the overhanging slab of the bridge superstructure and to pay off the work scaffolding, so it is difficult to avoid dangerous work because it is a high place work.

  In view of the above circumstances, an object of the present invention is to provide a method for constructing a wall rail of an overhanging PC bridge that can be constructed in a short construction period and at low cost and has high finishing accuracy.

The construction method of the wall rail of the overhanging PC bridge according to the present invention that achieves the above-mentioned object is provided with an overhanging work and a mounting portion capable of adjusting the standing posture in the overhanging of the bridge superstructure in the PC bridge. promote walls railings outer surface precast concrete panels with parallel and work temporarily fixed to the wall railings position above SL bridge superstructure simultaneously, after work end of the pier construction, erected in the wall railings outer surface precast concrete panels Adjusting the posture to make a highly precise railing arrangement, fixing this wall railing outer surface precast concrete panel to the above wall railing position, and then arranging the wall railing bar reinforcement, then standing up the wall railing inner form forming frame The concrete is characterized in that concrete is placed in a space between the wall rail outer surface precast concrete panel and the wall rail inner surface forming form.

According to the construction method of the walls railings overhanging erection PC bridge of the present invention, the work of the overhang erection, order to proceed in parallel and work temporarily fixing the wall railings outer surface precast concrete panels simultaneously, the temporary fixing For this work, a work scaffold used for the overhang work can be used. Moreover, according to the construction method of the wall rail of the overhanging construction PC bridge according to the present invention, after the overhanging construction work is completed, the standing position of the precast concrete panel of the wall height rail outer surface is adjusted and fixed. Even if the height of the upper surface of the overhanging slab changes at the construction stage, the height of the wall rail and the finish of the plane alignment can be adjusted with high accuracy by the adjustment. Moreover, according to the construction method of the wall rail of the overhanging PC bridge according to the present invention, after completion of the overhanging construction, a scaffolding is newly provided outside the wall rail position in the bridge superstructure, or the support work is performed from the ground. Since it is not necessary to assemble or install a work cart separately, the construction period can be shortened compared to the conventional method, and the cost can be reduced.

  Here, in the construction method of the wall rail of the overhanging PC bridge according to the present invention, the bridge superstructure has a recess at the wall rail position where the lower end of the wall rail external surface precast concrete panel is fitted. Is preferred.

  According to such a preferable embodiment, it is possible to ensure a wide adjustment range of the vertical position of the precast concrete panel of the wall rail for the bridge superstructure.

  Moreover, the construction method of the wall rail of the overhanging PC bridge according to the present invention includes the first elongated hole in which the adjustment of the standing posture is fixed to the side surface on the space side of the wall rail outer surface precast concrete panel. A panel side fixing bracket having a second long hole extending in a direction intersecting with the first long hole, which is fixed to the bridge superstructure adjacent to the wall rail position on the space side of the wall rail position. Standing posture comprising a bridge upper work side metal fitting having a connecting metal fitting that connects the panel side fixing metal fitting and the bridge upper work side metal fitting through the first elongated hole and the second elongated hole. Using the adjusting means, the position of the connection between the panel side fixing bracket and the bridge upper work side bracket by the connecting bracket is selected in each of the first long hole and the second long hole. The wall height for the bridge superstructure It is also preferable is to adjust the vertical height position and inclination of the outer surface precast concrete panels.

  According to such a preferred embodiment, it is possible to easily adjust the vertical height position and inclination of the wall height column outer surface precast concrete panel with respect to the bridge superstructure with a simple mechanism.

  ADVANTAGE OF THE INVENTION According to this invention, the construction method of the wall rail of the overhanging construction PC bridge which can be constructed in a short construction period and at low cost and has high finishing accuracy is provided.

It is a side view which shows construction of the prestressed concrete box girder bridge (PC box girder bridge) by the overhang construction method to which one Embodiment of this invention was applied. It is an enlarged view of the A section shown in FIG. It is sectional drawing at right angles to a bridge axis of the side edge part of an existing bridge body block. It is sectional drawing at right angles to a bridge axis of the side edge part of an existing bridge body block. It is sectional drawing at right angles to a bridge axis of the side edge part of an existing bridge body block. It is a side view of the precast concrete panel shown in FIG. It is an enlarged view of the B section shown in FIG. It is a figure which shows another form of the existing bridge body block side metal fitting. It is sectional drawing at right angles to a bridge axis of the side edge part of an existing bridge body block. It is sectional drawing at right angles to a bridge axis explaining the construction of a concrete wall rail. It is sectional drawing at right angles to the bridge axis of the constructed concrete wall rail.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a side view showing construction of a prestressed concrete box girder bridge (PC box girder bridge) by an overhang construction method to which an embodiment of the present invention is applied.

  In the overhang construction method, a bridge block divided into 3 to 5 m in the direction of the bridge axis is extended in the direction of the bridge axis while using a work vehicle for overhang construction to balance the bridge from side to side. It is a construction method that constructs the bridge superstructure by adding and constructing.

  In FIG. 1, the construction of the overhanging slab has already been completed for the piers P1 and P4, and the bridge block 102 is used while the piers P2 and P3 are balanced to the left and right in the bridge axis direction using the overhanging construction work vehicle 110. , 103 are projected one block at a time. The bridge blocks 101 and 104 of the piers P1 and P4 are connected to each abutment 105 with cast-in-place concrete using support, and the bridges extending from the piers P2 and P3 are waited for and connected at the closing part. Complete a series of bridge bodies.

  Hereinafter, with reference to FIG. 2, the construction of the PC box girder bridge by the overhang construction method will be described in detail.

  FIG. 2 is an enlarged view of part A shown in FIG. FIG. 2 shows a state in which the pier head and the column head are constructed at the upper end of the pier P2, and the bridge block 102 is being extended from the column head one block at a time like 102a, 102b,. ing. More specifically, FIG. 2 shows a stage where the bridge body block 102e is completed and the next new bridge body block 102f is being constructed. At this stage, a wall rail is constructed on the existing bridge block 102e in parallel.

  In the overhanging construction work vehicle 110 shown in FIG. 2, a horizontal beam 112 is hung on a quadrilateral main frame 111, and a steel bar 113 is suspended from the horizontal beam 112. A block formwork support 114 and work suspension scaffolds 115 and 116 are attached. The work suspension scaffolds 115 and 116 straddle the existing bridge body block 102e and the new bridge body block 102f. The main frame 111 is placed on the rail 120 so as to be able to move forward and backward, and a reaction force support device 117 is provided at the tail end of the main frame 111.

  First, the rail 120 that can be moved in the direction of the bridge axis is temporarily temporarily fixed on the existing bridge body blocks 102c, 102d, and 102e, and the overhanging construction work vehicle 110 placed on the rail 120 is attached to the existing bridge body block. Advance to 102d, 102e. Further, the overhanging construction work vehicle 110 is fixed on the rail 120 by locking the reaction force support device 117 to the rail 120.

  Next, on the formwork support 114 attached to the steel rod 113 suspended from the cross beam 112 on the main frame 111 of the overhanging construction work vehicle 110, the formwork of the next new bridge body block 102f and Assemble the reinforcing bars and place concrete in the formwork. The reaction force of the placed concrete is supported by the reaction force support device 117. Further, at the time of placing the concrete, an anchor 10 (see FIG. 3) for fixing an existing bridge block side metal fitting 144 (see FIG. 5), which will be described later, protrudes from both ends of the upper surface of the new bridge block 102f. Embed in the state of letting. After that, the concrete is cured, and prestress in the direction of the bridge axis is introduced into the cured concrete. Thereby, the new bridge body block 102f which has the anchor 10 in the upper surface both-ends part of the new bridge body block 102f is constructed | assembled.

  Further, in parallel with the construction of the new bridge block 102f described with reference to FIG. 2, the precast concrete panel 140 (see FIG. 5), which is the outer surface of the wall height column, is temporarily fixed at the wall column position of the existing bridge block 102e. To do. This precast concrete panel 140 is an embodiment of the wall rail outer surface precast concrete panel referred to in the present invention. Hereinafter, temporary fixing of the precast concrete panel 140 will be described with reference to FIGS.

  FIG. 3 is a sectional view of the side end portion of the existing bridge body block 102e perpendicular to the bridge axis.

  After the concrete strength of the new bridge block 102f reaches a predetermined strength, as shown in FIG. 3, pre-stress in a direction orthogonal to the bridge axis direction is introduced to the existing bridge block 102e using a jack 20. I ’m nervous.

  In addition, as shown in FIG. 3, the existing bridge body block side metal fitting 144 (refer FIG. 5) mentioned later embedded at the side edge part of the existing bridge body block 102e was embedded at the time of concrete placement of this existing bridge body block 102e. An anchor 10 is provided with the tip protruding.

  FIG. 4 is a cross-sectional view perpendicular to the bridge axis of the side end portion of the existing bridge block 102e.

  A side end portion of the existing bridge block 102e on the formwork support member 114 attached to the steel rod 113 suspended from the cross beam 112 on the main frame 111 of the overhanging construction work vehicle 110 (see FIG. 1). The formwork 30 and the reinforcing bar of the drainer 130 to be constructed are assembled, and concrete is placed in the formwork 30. At the time of placing the concrete, positioning bolts 11 for positioning the precast concrete panel 140 (see FIG. 5) are embedded with the tip protruding. Further, the mold 30 used here is formed with a convex portion 31 so that a concave portion 131 (see FIG. 7) into which the lower end of the precast concrete panel 140 is fitted is formed at the side end portion of the drainer 130. . After that, the concrete is cured. Thereby, the drainer 130 which has the recessed part 131 in which the lower end of the precast concrete panel 140 fits in the side edge part of the existing bridge body block 102e is built. The portion where the recess 131 of the drainer 130 is formed is the wall rail position where the precast concrete panel 140 is installed. Since the portion where such a recess 131 is formed is the wall rail position, a wide adjustment range of the vertical position of the precast concrete panel 140 for the bridge superstructure is ensured.

  FIG. 5 is a cross-sectional view of the side end portion of the existing bridge body block 102e perpendicular to the bridge axis. FIG. 6 is a side view of the precast concrete panel 140 shown in FIG. FIG. 7 is an enlarged view of a portion B shown in FIG.

  As described above, the anchor 10 embedded at the time of concrete placement of the existing bridge block 102e is provided at the side end portion of the existing bridge block 102e with the tip protruding. Using this anchor 10, the existing bridge block side metal fitting 144 is fixed to the side end portion of the existing bridge block 102e. Although detailed description will be given later, this existing bridge block side metal fitting 144 is an embodiment of the bridge upper work side metal fitting referred to in the present invention.

  The precast concrete panel 140 is a panel having an outer surface of a wall rail provided with a mounting portion capable of adjusting a standing posture. More specifically, on the side surface of the precast concrete panel 140, a positioning fitting 141 that is locked to the positioning bolt and a vertical direction that is locked to the existing bridge body block side fitting 144 via the connecting fitting 143 are extended. A panel-side fixture 142 having a first elongated hole 142a is provided. The connecting metal fitting 143 is an embodiment of the connecting metal fitting according to the present invention, and the panel side fixing metal fitting 142 is an embodiment of the panel side fixing metal fitting according to the present invention.

  As shown in FIG. 7, the existing bridge body block side metal fitting 144 is in contact with the upper surface of the vertical member 1441, the existing bridge body block 102 e and the drainer 130 and is connected at the lower end of the vertical member 1441 to support the vertical member 1441. It consists of a combination with the material 1442. Further, the vertical member 1441 of the existing bridge block side metal fitting 144 is formed with a second long hole 144a extending in a direction orthogonal to the first long hole 142a of the panel side fixing metal fitting 142. And the connection metal fitting 143 is a metal fitting which penetrates the 1st long hole 142a and the 2nd long hole 144a, and connects the panel side fixing metal fitting 142 and the existing bridge body block side metal fitting 144. FIG. The combination of the panel side fixing bracket 142, the existing bridge body block side bracket 144 and the connecting bracket 143 is an embodiment of the standing posture adjusting means according to the present invention.

  FIG. 8 is a diagram showing another form of the existing bridge block side metal fitting 144.

  As shown in FIG. 8, the existing bridge block side metal fitting 144 is composed of a diagonal member 1443, a parallel member 1444 substantially parallel to the upper surface of the existing bridge block 102e, and the diagonal member 1441 and the parallel member fixed to the anchor 10. It may consist of a combination with a fixing member 1443 connected to 1442.

  Returning to FIGS. 5 to 7, the description of the temporary fixing of the precast concrete panel 140 will be continued.

  The precast concrete panel 140 is moved to the side end portion of the existing bridge body block 102e by using the overhanging construction work vehicle 110 (see FIG. 2), and the positioning bracket 141 of the precast concrete panel 140 is moved to the existing bridge body block 102e. The precast concrete panel 140 is installed at the wall rail position by engaging with the positioning bolts 11 provided in the drainer 130. In addition, after the precast concrete panel 140 is positioned, the panel-side fixture 142 of the precast concrete panel 140 and the existing bridge block side fixture 144 fixed to the side end portion of the existing bridge block 102e are connected to the connection fixture 143. Connect using. Thereby, the precast concrete panel 140 is temporarily fixed to the wall rail position.

  FIG. 9 is a sectional view of the side end portion of the existing bridge body block 102e perpendicular to the bridge axis.

  In the overhanging construction method according to the present embodiment, the support material for supporting the back surface of the protective fence 200 for the precast concrete panel 140 temporarily fixed at the wall rail position until the overhanging work is completed. Use as

  Returning to FIG. 2, the overhanging work after the new bridge body block 102f is constructed will be described.

  After the new bridge body block 102f is constructed and the precast concrete panel 140 is temporarily fixed at the wall rail position, the temporary fixing of the rail 120 is released to prepare for the construction of the next new bridge body block. The rail 120 is advanced on the block 102f, temporarily fixed again, and the overhanging construction work vehicle 110 is advanced to the constructed bridge body block 102f.

  Hereinafter, the work described with reference to FIGS. 2 to 9 is repeated, and the bridge block is added one after another while temporarily fixing the precast concrete panel 140. Then, the bridge body is connected in the middle of the pier, a continuous cable (not shown) is tensioned to introduce prestress in the bridge axis direction to the bridge superstructure, and overhanging work and temporary fixing of the precast concrete panel 140 Finish the work.

  With reference to FIGS. 5 to 7, the standing posture adjustment and fixing of the precast concrete panel 140 will be described.

  After tensioning the continuous cable (not shown) and introducing prestress in the direction of the bridge axis to the bridge superstructure, the position and height of the temporarily fixed precast concrete panel 140 are measured so as to be within a predetermined management range. The standing posture of the precast concrete panel 140 is adjusted to fix the precast concrete panel 140 to the wall rail position. More specifically, the temporarily fixed precast concrete panel 140 is temporarily loosened, and the position of the connection between the panel-side fixing bracket 142 and the existing bridge block-side bracket 144 by the connecting bracket 143 is changed to the first long hole 142a and By selecting within each of the second long holes 144a, the height position and inclination of the precast concrete panel 140 with respect to the bridge superstructure are adjusted. Thereafter, the panel-side fixture 142 and the existing bridge block-side fixture 144 are fixed again using the connecting fixture 143.

  FIG. 10 is a cross-sectional view perpendicular to the bridge axis for explaining the construction of the concrete wall rail. FIG. 11 is a cross-sectional view of the constructed concrete wall rail perpendicular to the bridge axis.

  After the standing posture of the precast concrete panel 140 is adjusted and fixed, the rebar of the wall rail is arranged, the wall rail inner surface forming form 150 is erected, and the precast concrete panel 140 and the wall rail inner surface forming form are arranged. A wall railing concrete is placed in a space between 150 and 150. Thereby, the concrete wall height column 160 is constructed.

  According to the embodiment described above, the precast concrete panel 140 serving as the outer wall of the wall rail is temporarily fixed simultaneously with the overhanging work. The working suspension scaffolds 115 and 116 used in the above can be used. Further, according to the present embodiment, after completion of the overhang construction work, the height of the upper surface of the overhanging slab is changed at the construction stage of the overhang construction in order to fix the precast concrete panel 140 after adjusting the standing posture. Even so, the height of the wall rails and the finish of the horizontal alignment can be adjusted with high accuracy by the adjustment. In addition, according to the present embodiment, after completion of the overhang construction work, a scaffolding is newly provided outside the wall rail position in the bridge superstructure, a support work is assembled from the ground, or a work carriage is separately installed. Therefore, the construction period can be shortened compared to the conventional method, and the cost can be reduced.

  In this embodiment, an example is described in which the bridge superstructure of the PC bridge is overhanged by cast-in-place concrete. However, the bridge superstructure of the PC bridge may be stretched using a precast member.

P1, P2, P3, P4 Piers 101, 102, 103, 104 Bridge block 105 Abutment 110 Mobile work vehicle for overhanging construction 111 Main frame 112 Cross beam 113 Steel bar 114 Form support material 115, 116 Work suspension scaffold Force support device 120 Rail 130 Drainer 131 Recess 140 Precast concrete panel 141 Positioning bracket 142 Panel side fixing bracket 142a First elongated hole 143 Connecting bracket 144 Existing bridge block side bracket 144a Second elongated hole 1441 Diagonal material 1442 Parallel member 1443 Fixing material 150 Wall railing inner form forming frame 160 Concrete wall railing 10 anchor 11 positioning bolt 20 jack 30 mold 31 convex part 200 construction protection fence

Claims (3)

Upon overhanging erection of a bridge superstructure in PC bridges, temporarily fixing the work of the installation out 該張, walls railings outer surface precast concrete panel with a standing設姿bias adjustable mounting unit to the wall railings position before Symbol bridges superstructure The wall height rail outer surface precast concrete panel is adjusted by adjusting the standing posture of the wall rail outer surface precast concrete panel, and the wall height rail outer surface precast concrete panel is After fixing the wall rail to the wall rail position, and then arranging the wall rail rebar, standing the wall rail inner surface forming form, between the wall rail outer surface precast concrete panel and the wall rail inner surface forming form A method of constructing a wall rail for a PC bridge overhanging, characterized in that concrete is placed in the space.   2. The construction of a wall rail for an overhanging PC bridge according to claim 1, wherein the bridge superstructure has a recess in the wall rail position where the lower end of the outer wall precast concrete panel is fitted. Method.   The adjustment of the standing posture is fixed to the side surface on the space side of the wall rail outer surface precast concrete panel, the panel side fixing bracket having a first long hole, and the wall on the space side of the wall rail position A bridge upper work side metal fitting having a second long hole extending in a direction intersecting with the first long hole, fixed to the bridge upper work adjacent to the railing position, the first long hole and the second long hole The panel-side fixing bracket and the bridge by the connecting bracket using a standing posture adjusting means that includes a connecting bracket that connects the panel-side fixing bracket and the bridge upper work-side bracket. By selecting the position of connection with the superstructure side metal fitting in each of the first long hole and the second long hole, the height of the precast concrete panel in the vertical direction of the wall height column outer surface with respect to the bridge superstructure Position According to claim 1 or 2 method of constructing walls railings overhanging erection PC bridge wherein a and adjusts the inclination.

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